lf.c File Reference

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#include "include/cm.h"
#include <argp.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <linux/limits.h>
#include <pthread.h>
#include <pwd.h>
#include <regex.h>
#include <stdatomic.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

Include dependency graph for lf.c:

Go to the source code of this file.

Macros
#define	_GNU_SOURCE
#define	DT_LNK_DIR   14
#define	print_file_type(mask, lf_type, dt_type, name)

Typedefs
typedef struct TaskNode	TaskNode

Functions
void	debug_out (SearchFilters *f, int argc, char **argv, int threads)
	Output debug information about the search filters and configuration.
TaskNode *	dequeue_dir ()
	Dequeue a directory dir_path for processing by finder threads.
void	enqueue_dir (TaskNode *new_task)
	Enqueue a directory dir_path for processing by finder threads.
void *	finder (void *arg)
	Worker thread function to process directories from the queue.
bool	init_find (SearchFilters *f, int argc, char **argv)
	Initialize the file search based on the provided SearchFilters and start finder threads.
bool	is_dirsys (const char *)
bool	is_hidden (const char *)
int	main (int argc, char **argv)
int	scan_file (char *file_spec, const SearchFilters *f, const unsigned char effective_type)
	scan a single file against search filters
void	sort_lf_output (SearchFilters *, int, char **)

Variables
atomic_int	active_tasks = 0
const char *	argp_program_bug_address = "billxwaller@gmail.com"
const char *	argp_program_version = CM_VERSION
pthread_cond_t	cond_var = PTHREAD_COND_INITIALIZER
char *	debug_p
const char	doc []
char *	exec
size_t	file_count = 0
char *	file_types_p
unsigned char const	lf_mask [15]
int	lfargc
char *	lfargs [3]
unsigned int	nthreads
char *	perms_p
TaskNode *	qhead = NULL
TaskNode *	qtail = NULL
pthread_mutex_t	queue_mutex = PTHREAD_MUTEX_INITIALIZER
int	shutdown = 0
int	termination_status = EXIT_SUCCESS
struct tm	tm_info

Detailed Description

list files matching a regular expression

NOTICE: This file is part of the lf project, which is currently under development. There are two reasons not to use it at this time. First, it is not yet fully functional and may contain bugs or incomplete, unoptimized code. Second, the API and features are still being finalized, so using it now may lead to compatibility issues in the future as changes are made. Once the project is more mature and stable, this file will be ready for use. In the meantime, it serves as a work in progress and may be subject to significant changes as development continues.

Thank you for your patience and understanding.

Author

Bill Waller Copyright (c) 2025 MIT License billx.nosp@m.wall.nosp@m.er@gm.nosp@m.ail..nosp@m.com

Date

2026-02-09

Definition in file lf.c.

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Definition at line 21 of file lf.c.

DT_LNK_DIR

#define DT_LNK_DIR   14

Definition at line 101 of file lf.c.

print_file_type

#define print_file_type	(		mask,
			lf_type,
			dt_type,
			name )

Value:

{                                                           \
    fprintf(stderr, "%c %08b (%3d) %08b (%2d) %s\n",        \
            (mask & lf_type) ? '*' : ' ', lf_type, lf_type, \
            dt_type, dt_type, name);                        \
}

Definition at line 45 of file lf.c.

#define print_file_type(mask, lf_type, dt_type, name)           \
    {                                                           \
        fprintf(stderr, "%c %08b (%3d) %08b (%2d) %s\n",        \
                (mask & lf_type) ? '*' : ' ', lf_type, lf_type, \
                dt_type, dt_type, name);                        \
    }

Typedef Documentation

TaskNode

typedef struct TaskNode TaskNode

Definition at line 110 of file lf.c.

Function Documentation

debug_out()

void debug_out	(	SearchFilters *	f,
		int	argc,
		char **	argv,
		int	threads )

Output debug information about the search filters and configuration.

Parameters

f	A pointer to a SearchFilters struct containing the options and flags for filtering.
argc	The number of command-line arguments.
argv	The array of command-line argument strings.
threads	The number of threads being used for the search.

This function prints detailed information about the configuration and search filters as well as each of the options and arguments used on the command line invoking lf. The output is sent to the standard error stream, which can be redirected to standard output making it suitable as documentation for an audit trail.

Definition at line 620 of file lf.c.

                                                                     {
    char user_str[100];
    char ip_str[MAXLEN];
    int len = 0;
    int i;
    bool addspace_before = false;
    if (f->debug && (f->report_config || f->report_info || f->report_all)) {
        fprintf(stderr, "%s,%s,%s,", get_local_timestamp(), get_user_str(user_str, 100), get_ip_addresses(ip_str, MAXLEN));
        for (i = 0; i < argc; i++) {
            len = len + strlen(argv[i]);
            if (len > 72) {
                fprintf(stderr, "\n");
                len = strlen(argv[i]);
                addspace_before = false;
            }
            if (addspace_before) {
                fprintf(stderr, " ");
                len++;
            }
            fprintf(stderr, "%s", argv[i]);
            addspace_before = true;
        }
        fprintf(stderr, "\n\n");
        fprintf(stderr, "%s\n\n", CM_VERSION);
        fprintf(stderr, "lf debug      %s\n",
                f->debug ? "true" : "     false");
        fprintf(stderr, "  1-config      %s\n",
                f->report_config ? "true" : "|    false");
        fprintf(stderr, "  2-info        %s\n",
                f->report_info ? "true" : "|    false");
        fprintf(stderr, "  3-warnings    %s\n",
                f->report_warnings ? "true" : "|    false");
        fprintf(stderr, "  4-errors      %s\n",
                f->report_errors ? "true" : "|    false");
        fprintf(stderr, "  5-badlinks    %s\n",
                f->report_trace ? "true" : "|    false");
        fprintf(stderr, "  6-trace       %s\n",
                f->report_trace ? "true" : "|    false");
        fprintf(stderr, "  7-all         %s\n",
                f->report_all ? "true" : "|    false");
        fprintf(stderr, "  8-only_errors %s\n",
                f->only_errors ? "true" : "|    false");
        fprintf(stderr, "\n");
        fprintf(stderr, "Count files: %s\n", f->count ? "true" : "false");
        fprintf(stderr, "Count only: %s\n", f->count_silently ? "true" : "false");
        fprintf(stderr, "\n");
        fprintf(stderr, "Search directory: %s\n\n", f->base_path);
        if (f->max_depth == 0)
            fprintf(stderr, "Max depth 0 (unlimited)\n\n");
        else
            fprintf(stderr, "Max depth %d\n\n", f->max_depth);
        fprintf(stderr, "Using %d threads\n\n", threads);
        fprintf(stderr, "File types preceeded by an asterisk (\"*\") will be included:\n\n");
        fprintf(stderr, "  LF type        DT type\n");
        print_file_type(f->include_types, LF_FIFO, DT_FIFO, "FIFO    p-named pipe");
        print_file_type(f->include_types, LF_CHR, DT_CHR, "CHR     c-character device");
        print_file_type(f->include_types, LF_DIR, DT_DIR, "DIR     d-directory");
        print_file_type(f->include_types, LF_BLK, DT_BLK, "BLK     b-block device");
        print_file_type(f->include_types, LF_REG, DT_REG, "REG     f-regular file");
        print_file_type(f->include_types, LF_LNK, DT_LNK, "LINK    l-symbolic link");
        print_file_type(f->include_types, LF_SOCK, DT_SOCK, "SOCK    s-socket");
        print_file_type(f->include_types, LF_UNKNOWN, DT_UNKNOWN, "UNKNOWN u-unknown");
        fprintf(stderr, "\n");
        fprintf(stderr, "f->include_types  = %08b\n", f->include_types);
        fprintf(stderr, "f->suppress_types = %08b\n", f->suppress_types);
        fprintf(stderr, "\n");
        if (f->flags & LF_USER)
            fprintf(stderr, "User: %s (%ju)\n", f->user_name, f->user_id);
        if (f->include_perms) {
            if (f->include_perms & LF_IXUSR)
                fprintf(stderr, "    %08b Execute\n", LF_IXUSR);
            if (f->include_perms & LF_IWUSR)
                fprintf(stderr, "    %08b Write\n", LF_IWUSR);
            if (f->include_perms & LF_IRUSR)
                fprintf(stderr, "    %08b Read\n", LF_IRUSR);
            if (f->include_perms & LF_ISUID)
                fprintf(stderr, "    %08b SETUID\n", LF_ISUID);
            if (f->include_perms & LF_ISGID)
                fprintf(stderr, "    %08b SETGID\n", LF_ISGID);
        }
        fprintf(stderr, "\n");
        if (f->flags & LF_REGEX)
            fprintf(stderr, "Include regex: %s\n\n", f->re);
        if (f->flags & LF_EXC_REGEX)
            fprintf(stderr, "Exclude regex: %s\n\n", f->ere);
 
        if (f->after) {
            char buf[32];
            format_local_timestamp(f->after, buf, sizeof(buf));
            fprintf(stderr, "Modified after: %s\n\n", buf);
        }
 
        if (f->before) {
            char buf[32];
            format_local_timestamp(f->before, buf, sizeof(buf));
            fprintf(stderr, "Modified before: %s\n\n", buf);
        }
 
        if (f->file_size_min) {
            const char *units[] = {"b", "Kb", "Mb", "Gb", "Tb", "Pb", "Eb"};
            off_t size = f->file_size_min;
            i = 0;
            while (size >= 1024 && i < 6) {
                size /= 1024;
                i++;
            }
            char buffer[32];
            ssnprintf(buffer, 32, "%ld %s", size, units[i]);
            fprintf(stderr, "Minimum file size: %s\n\n", buffer);
        }
        if (f->max_depth)
            fprintf(stderr, "Max depth: %d\n\n", f->max_depth);
        if (f->ignore_case)
            fprintf(stderr, "Ignore case in regex matching.\n\n");
        if (f->include_hidden)
            fprintf(stderr, "Include hidden files.\n\n");
        if (f->follow_links)
            fprintf(stderr, "Follow symbolic links.\n\n");
        if (f->sort)
            fprintf(stderr, "Sort output in ascending order.\n\n");
        if (f->sort_reverse)
            fprintf(stderr, "Sort output in reverse order.\n\n");
        if (f->report_config && !f->report_all)
            exit(EXIT_SUCCESS);
    }
    return;
}

References format_local_timestamp(), get_ip_addresses(), get_local_timestamp(), get_user_str(), LF_BLK, LF_CHR, LF_DIR, LF_EXC_REGEX, LF_FIFO, LF_IRUSR, LF_ISGID, LF_ISUID, LF_IWUSR, LF_IXUSR, LF_LNK, LF_REG, LF_REGEX, LF_SOCK, LF_UNKNOWN, LF_USER, and ssnprintf().

Referenced by init_find().

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dequeue_dir()

TaskNode * dequeue_dir

(

)

Dequeue a directory dir_path for processing by finder threads.

Returns

A pointer to a TaskNode containing the directory dir_path and depth, or NULL if the queue is empty and shutdown has been initiated.

This function removes and returns the next TaskNode from the global queue. It uses a mutex to ensure thread-safe access to the queue, and waits on a condition variable if the queue is empty. The function also checks for shutdown conditions to allow finder threads to exit gracefully when there is no more work to process.

Definition at line 790 of file lf.c.

                        {
    pthread_mutex_lock(&queue_mutex);
 
    // Wait until there is a task in the queue or shutdown has been
    // initiated. The loop condition checks if the queue is empty (qhead ==
    // NULL) and if shutdown has not been initiated (!shutdown). If both
    // conditions are true, it means there are no tasks to process and the
    // thread should wait. The thread will be woken up when a new task is
    // enqueued (via pthread_cond_signal in enqueue_dir) or when shutdown is
    // initiated (via pthread_cond_broadcast in enqueue_dir or when
    // active_tasks count reaches zero). This ensures that threads do not
    // wait indefinitely when there are no tasks left to process and allows
    // for a graceful shutdown of the program.
    while (qhead == NULL && !shutdown) {
        // If there are no active tasks and the queue is empty, we can
        // safely initiate shutdown. This check is necessary to prevent a
        // potential race condition where a thread could be waiting
        // indefinitely on the condition variable if all tasks have been
        // completed and no new tasks will be enqueued. By checking the
        // active_tasks count, we can determine when it's safe to signal
        // shutdown
        if (atomic_load(&active_tasks) == 0) {
            shutdown = 1;
            // and wake up any waiting threads so they can exit gracefully.
            pthread_cond_broadcast(&cond_var);
            break;
        }
        // Wait for a task to be enqueued or shutdown initiated. The thread
        // will be woken up when a new task is added to the queue (via
        // pthread_cond_signal in enqueue_dir) or when shutdown is initiated
        // (via pthread_cond_broadcast in enqueue_dir or when active_tasks
        // count reaches zero). This allows the thread to check the
        // conditions again and either process a new task or exit if
        // shutdown has been initiated.
        pthread_cond_wait(&cond_var, &queue_mutex);
    }
    if (shutdown && qhead == NULL) {
        pthread_mutex_unlock(&queue_mutex);
        return NULL;
    }
    TaskNode *temp = qhead;
    // Move the head pointer to the next task in the queue. If the queue
    // becomes empty after this operation (qhead becomes NULL), we also set
    // qtail to NULL to indicate that the queue is empty. This ensures that
    // both qhead and qtail accurately reflect the state of the queue,
    // preventing potential issues with enqueuing new tasks or checking for
    // an empty queue in future operations.
    qhead = qhead->next_task;
    if (!qhead)
        qtail = NULL;
    atomic_fetch_add(&active_tasks, 1);
    pthread_mutex_unlock(&queue_mutex);
    return temp;
}

References active_tasks, cond_var, qhead, qtail, queue_mutex, and shutdown.

Referenced by finder().

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enqueue_dir()

void enqueue_dir

(

TaskNode *

new_task

)

Enqueue a directory dir_path for processing by finder threads.

Parameters

new_task

A pointer to a TaskNode containing the directory path and depth to be enqueued for processing by finder threads.

This function adds a new TaskNode to the global queue of directories to be processed by finder threads. It uses a mutex to ensure thread-safe access to the queue and signals one waiting thread that a new task is available. If shutdown has been initiated, the signal will wake up any waiting threads so they can check the shutdown condition and exit gracefully.

Definition at line 757 of file lf.c.

                                     {
    pthread_mutex_lock(&queue_mutex);
    if (qtail)
        // Add the new task to the end of the queue. If qtail is not NULL,
        // it means there are already tasks in the queue, so we set the
        // next_task pointer of the current tail to point to the new task.
        // This effectively adds the new task to the end of the queue.
        qtail->next_task = new_task;
    else
        // If qtail is NULL, it means the queue is currently empty, so we
        // set qhead to point to the new task, making it the first and only
        // task in the queue
        qhead = new_task;
    // Finally, we update qtail to point to the new task, ensuring that it
    // always points to the last task in the queue.
    qtail = new_task;
    // Signal one waiting thread that a new task is available. If shutdown
    // hasn't been initiated, this will wake up a finder thread to process
    // the new task. If shutdown has been initiated, the signal will wake up
    // any waiting threads so they can check the shutdown condition and exit
    // gracefully.
    pthread_cond_signal(&cond_var);
    pthread_mutex_unlock(&queue_mutex);
}

References cond_var, qhead, qtail, and queue_mutex.

Referenced by finder(), and init_find().

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finder()

void * finder

(

void *

arg

)

Worker thread function to process directories from the queue.

Parameters

arg	Pointer to the SearchFilters struct containing the options and flags for filtering.

Returns

NULL

This function continuously dequeues directory dir_path from the global queue and processes them. For each directory, it lists its contents and applies the specified filters to each file. If a subdirectory is found and it meets the criteria for further searching (e.g., not hidden if hidden files are suppressed, and within max depth), it is enqueued for processing. The function uses atomic operations to track active tasks and condition variables to manage thread synchronization and shutdown when all work is complete.

Definition at line 857 of file lf.c.

                        {
    SearchFilters *f = (SearchFilters *)arg;
    char lnk_path[PATH_MAX] = {'\0'};
    // regmatch_t pmatch;
 
    while (1) {
        TaskNode *current_task = dequeue_dir();
        if (!current_task)
            break;
 
        //-------------------------------------------------------------
        // Open the directory for reading. We use openat with AT_FDCWD to
        // open the directory specified by current_task->dir_path, and then
        // use fdopendir to get a DIR* stream for reading the directory
        // entries. This approach allows us to handle directories with
        // special characters in their names more robustly, as it avoids
        // issues that can arise with functions like opendir that take a
        // path string directly. If openat or fdopendir fails, we log the
        // error (if debugging is enabled), clean up resources for the
        // current task, and continue to the next iteration of the loop to
        // process another task.
        int dir_fd =
            openat(AT_FDCWD, current_task->dir_path, O_RDONLY | O_DIRECTORY);
        if (dir_fd == -1) {
            if (f->debug && (f->report_warnings || f->report_errors ||
                             f->report_badlinks || f->report_all))
                fprintf(stderr, "OPEN_FAIL,%s,%s\n", current_task->dir_path,
                        strerror(errno));
            termination_status = EXIT_FAILURE;
            free(current_task->dir_path);
            free(current_task->history);
            free(current_task);
            atomic_fetch_sub(&active_tasks, 1);
            pthread_cond_broadcast(&cond_var);
            continue;
        }
        DIR *dir = fdopendir(dir_fd);
        if (dir == NULL) {
            if (f->debug && (f->report_warnings || f->report_errors ||
                             f->report_badlinks || f->report_all))
                fprintf(stderr, "\nFDOPENDIR_FAIL,%s,%s\n",
                        current_task->dir_path, strerror(errno));
            close(dir_fd);
            termination_status = EXIT_FAILURE;
            free(current_task->dir_path);
            free(current_task->history);
            free(current_task);
            atomic_fetch_sub(&active_tasks, 1);
            pthread_cond_broadcast(&cond_var);
            continue;
        }
        // unsigned char real_type;
        //-------------------------------------------------------------
        unsigned char effective_type;
        char full_path[PATH_MAX] = {'\0'};
        struct dirent *entry;
        while ((entry = readdir(dir)) != NULL) {
            struct stat st;
            stpcpy(stpcpy(stpcpy(full_path, current_task->dir_path), "/"),
                   entry->d_name);
            // Get link's metadata
            int rc;
            // We use fstatat with AT_SYMLINK_NOFOLLOW to get the metadata
            // of the symbolic link itself, rather than the target it points
            // to. This allows us to determine if the entry is a symbolic
            // link and handle it according to the user's options (e.g.,
            // whether to follow links or not). If fstatat fails, we log the
            // error (if debugging is enabled) and continue to the next
            // entry without processing this one further.
            rc = fstatat(AT_FDCWD, full_path, &st, AT_SYMLINK_NOFOLLOW);
            if (rc == -1) {
                if (f->debug && (f->report_errors || f->report_warnings ||
                                 f->report_badlinks || f->report_all))
                    fprintf(stderr, "LSTAT_FAIL,%s,%s\n", full_path,
                            strerror(errno));
                termination_status = EXIT_FAILURE;
                continue;
            }
            effective_type = (st.st_mode & S_IFMT) >> 12;
            // Determine the real type of the entry. If the entry is a
            // symbolic link, we set real_type to DT_LNK and then attempt to
            // get the metadata of the target it points to using fstatat
            // without AT_SYMLINK_NOFOLLOW. This allows us to determine the
            // effective type of the entry based on the target's metadata,
            // which is important for deciding how to process it (e.g.,
            // whether it's a directory that we should enqueue for further
            // searching). If fstatat fails when trying to get the target's
            // metadata, we log the error (if debugging is enabled) but
            // continue processing the entry based on its symbolic link
            // metadata.
            if (S_ISLNK(st.st_mode)) {
                // Get the target's metadata
                rc = fstatat(AT_FDCWD, full_path, &st, 0);
                if (rc == -1) {
                    if (f->debug && (f->report_all || f->report_warnings ||
                                     f->report_errors || f->report_badlinks)) {
                        fprintf(stderr, "STAT_FAIL,%s,%s\n", full_path,
                                strerror(errno));
                    }
                    termination_status = EXIT_FAILURE;
                    continue;
                }
                if (f->follow_links)
                    effective_type = (st.st_mode & S_IFMT) >> 12;
            }
            if (effective_type != DT_DIR) {
                if (is_hidden(entry->d_name)) {
                    if (!f->include_hidden)
                        continue;
                } else if (f->hidden_only)
                    continue;
            } else {
                if (is_dirsys(entry->d_name))
                    continue;
                // Determine the effective type of the entry. We use the st_mode
                // field from the stat struct to determine the file type by
                // applying the S_IFMT mask and shifting it to get a value that
                // corresponds to the DT_* constants. If the entry is a symbolic
                // link and the user has chosen not to follow links, we treat it
                // as a directory for the purpose of deciding whether to enqueue
                // it for further searching. This allows us to handle symbolic
                // links that point to directories in a way that respects the
                // user's options while still allowing for traversal of linked
                // directories if desired.
                //
                // Check for cycles by comparing the current
                // directory's dev/inode with the history of dev/inode pairs
                // from parent directories. If a match is found, it
                // indicates a cycle and we skip processing this directory.
                bool cycle_found = false;
                if (f->debug && (f->report_trace || f->report_all))
                    fprintf(stderr, "Checking for cycles in: %s\n", full_path);
                for (int i = 0; i < current_task->depth; i++) {
                    if (f->debug && (f->report_trace || f->report_all)) {
                        if (current_task->history[i].ino == st.st_ino)
                            fprintf(stderr, "%3d %ju %ju<===========\n", i,
                                    current_task->history[i].ino, st.st_ino);
                        else
                            fprintf(stderr, "%3d %ju %ju\n", i,
                                    current_task->history[i].ino, st.st_ino);
                    }
                    if (current_task->history[i].dev == st.st_dev &&
                        current_task->history[i].ino == st.st_ino) {
                        cycle_found = true;
                        break;
                    }
                }
                if (cycle_found) {
                    if (f->debug && (f->report_warnings || f->report_errors ||
                                     f->report_trace || f->report_badlinks ||
                                     f->report_all)) {
                        ssize_t len =
                            readlink(full_path, lnk_path, sizeof(lnk_path) - 1);
                        if (len != -1) {
                            lnk_path[len] = '\0';
                            fprintf(stderr, "CYCLIC_LINK,%s,%s\n", full_path,
                                    lnk_path);
                        } else
                            fprintf(stderr, "CYCLIC_LINK,%s\n", full_path);
                    }
                    termination_status = EXIT_FAILURE;
                    continue;
                }
                //-------------------------------------------------------
                // Create a new TaskNode for the subdirectory and enqueue it
                // for processing by finder threads. We duplicate the
                // current history of dev/inode pairs and add the current
                // directory's dev/inode to the new history for the child
                // task. This allows us to maintain a record of the
                // directories we've visited in the current path, which is
                // essential for cycle detection. By checking this history
                // for each new directory we encounter, we can effectively
                // prevent infinite loops caused by symbolic links or hard
                // links that create cycles in the directory structure.
                //
                // What about using realloc? NO! All the directories in this
                // subdirectory must share the same history array.
                if (f->max_depth != 0 && current_task->depth + 1 == f->max_depth)
                    continue;
                TaskNode *child_task = malloc(sizeof(TaskNode));
                child_task->dir_path = strdup(full_path);
                child_task->depth = current_task->depth + 1;
                child_task->next_task = NULL;
                child_task->history =
                    malloc((child_task->depth) * sizeof(History));
                if (current_task->depth > 0) {
                    memcpy(child_task->history, current_task->history,
                           sizeof(History) * current_task->depth);
                }
                child_task->history[current_task->depth].dev = st.st_dev;
                child_task->history[current_task->depth].ino = st.st_ino;
                enqueue_dir(child_task);
            }
            if (f->hidden_only && !is_hidden(entry->d_name))
                continue;
            scan_file(full_path, f, effective_type);
        }
        closedir(dir);
        free(current_task->dir_path);
        free(current_task->history);
        free(current_task);
        atomic_fetch_sub(&active_tasks, 1);
    }
    return NULL;
}

References active_tasks, cond_var, dequeue_dir(), enqueue_dir(), is_dirsys(), is_hidden(), scan_file(), and termination_status.

Referenced by init_find().

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init_find()

bool init_find	(	SearchFilters *	f,
		int	argc,
		char **	argv )

Initialize the file search based on the provided SearchFilters and start finder threads.

Parameters

f	A pointer to a SearchFilters struct containing the options and flags for filtering.
argc	The number of command-line arguments.
argv	The array of command-line argument strings.

Returns

true if the search was initialized successfully, false if an error occurred during initialization (e.g., regex compilation failure).

This function processes the flags and options specified in the SearchFilters struct to set up the search criteria. It compiles any regular expressions provided by the user and initializes the queue with the base directory. It then creates a number of finder threads equal to the number of CPU cores to perform the directory traversal and file scanning concurrently. The function waits for all finder threads to complete before cleaning up resources and returning.

suppress file types that aren't included

Definition at line 523 of file lf.c.

                                                        {
    if (!f->include_types)
        f->include_types = 0xff;
    if (f->include_types)
        f->suppress_types = f->include_types ^ 0xff;
    // LF_HIDE = 0 - include hidden files,
    // LF_HIDE = 1 - suppress hidden files
    f->include_hidden = !(f->flags & LF_HIDE);
    int reti = 0;
    f->reg_flags = REG_EXTENDED;
    if (f->flags & LF_ICASE)
        f->reg_flags |= REG_ICASE;
    if (f->flags & LF_REGEX) {
        reti = regcomp(&f->compiled_re, f->re, f->reg_flags);
        if (reti) {
            fprintf(stderr, "lf: '%s' Invalid pattern\n", f->re);
            regfree(&f->compiled_re);
            return false;
        }
    }
    if (f->flags & LF_EXC_REGEX) {
        reti = regcomp(&f->compiled_ere, f->ere, f->reg_flags);
        if (reti) {
            fprintf(stderr, "lf: '%s' Invalid exclude pattern\n", f->ere);
            regfree(&f->compiled_ere);
            return false;
        }
    }
    unsigned int nprocs = get_nprocs();
    if (nthreads > 1 && nthreads < nprocs)
        nthreads += nprocs;
    else {
        if (nthreads == 0)
            nthreads = ((nprocs * 40) / 99) + 1;
    }
    if (nthreads > nprocs)
        nthreads = nprocs - 1;
 
    debug_out(f, argc, argv, nthreads);
    //--------------------------------------------------------------------
    // Create and enqueue the first TaskNode
    struct stat st;
    if (stat(f->base_path, &st) == 0) {
        if (S_ISDIR(st.st_mode)) {
            TaskNode *child_task = malloc(sizeof(TaskNode));
            child_task->dir_path = strdup(f->base_path);
            child_task->depth = 0;
            child_task->next_task = NULL;
            child_task->history = malloc(sizeof(History));
            child_task->history[0].dev = st.st_dev;
            child_task->history[0].ino = st.st_ino;
            enqueue_dir(child_task);
            pthread_t threads[nthreads];
            for (unsigned int i = 0; i < nthreads; i++) {
                pthread_create(&threads[i], NULL, finder, f);
            }
            pthread_mutex_lock(&queue_mutex);
            while (!shutdown) {
                pthread_cond_wait(&cond_var, &queue_mutex);
            }
            pthread_mutex_unlock(&queue_mutex);
            for (unsigned int i = 0; i < nthreads; i++)
                pthread_join(threads[i], NULL);
        } else {
            fprintf(stderr,
                    "Warning: Base path '%s' is not a directory. No "
                    "files will be found.\n",
                    f->base_path);
        }
    }
    //--------------------------------------------------------------------
    // End Program
    if (f->flags & LF_REGEX) {
        regfree(&f->compiled_re);
    }
    if (f->flags & LF_EXC_REGEX) {
        regfree(&f->compiled_ere);
    }
    free(f->base_path);
    free(f->user_name);
    free(f->re);
    free(f->ere);
    free(f);
    if (reti)
        return false;
    return true;
}

References cond_var, debug_out(), enqueue_dir(), finder(), LF_EXC_REGEX, LF_HIDE, LF_ICASE, LF_REGEX, nthreads, queue_mutex, and shutdown.

Referenced by main(), and sort_lf_output().

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is_dirsys()

bool is_dirsys

(

const char *

name

)

Definition at line 1073 of file lf.c.

                                 {
    if (name[0] == '.') {
        if (name[1] == '\0')
            return true;
        if (name[1] == '.' && name[2] == '\0')
            return true;
    }
    return false;
}

Referenced by finder().

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is_hidden()

bool is_hidden

(

const char *

name

)

Definition at line 1063 of file lf.c.

                                 {
    if (name[0] == '.') {
        if (name[1] == '\0')
            return false;
        if (name[1] == '.' && name[2] == '\0')
            return false;
        return true;
    }
    return false;
}

Referenced by finder().

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main()

int main	(	int	argc,
		char **	argv )

Definition at line 389 of file lf.c.

                                {
 
    SearchFilters *f = (SearchFilters *)calloc(1, sizeof(SearchFilters));
    f->ignore_case = false;
    f->sort = false;
    f->sort_reverse = false;
    f->include_hidden = false; // By default, hidden files are suppressed. Use
                               // -H to include them.
    // LF_HIDE = 0 - include hidden files,
    // LF_HIDE = 1 - suppress hidden files
    f->hidden_only = false;
    f->flags |= LF_HIDE;     // Turn hide flag on
    f->follow_links = false; // By default, symbolic links are not followed. Use
                             // -L to follow them.
    f->count = false;
    f->count_silently = false;
    char tmp_str[PATH_MAX];
    argp_parse(&argp, argc, argv, 0, 0, f);
    if (lfargc > 0) {
        strnz__cpy(tmp_str, lfargs[0], MAXLEN - 1);
        expand_tilde(tmp_str, MAXLEN - 1);
        if (is_directory(tmp_str) || is_symlink_to_dir(tmp_str)) {
            f->base_path = strdup(tmp_str);
        } else if (is_valid_regex(lfargs[0])) {
            f->re = strdup(lfargs[0]);
            f->flags |= LF_REGEX;
        } else {
            fprintf(
                stderr,
                "lf: arg1: '%s' is neither a directory nor a valid regex.\n",
                lfargs[0]);
            exit(EXIT_FAILURE);
        }
    }
    if (lfargc > 1) {
        if (!f->base_path || f->base_path[0] == '\0') {
            strnz__cpy(tmp_str, lfargs[1], MAXLEN - 1);
            expand_tilde(tmp_str, MAXLEN - 1);
            if (is_directory(tmp_str) || is_symlink_to_dir(tmp_str))
                f->base_path = strdup(tmp_str);
        }
        if ((!(f->flags & LF_REGEX)) && is_valid_regex(lfargs[1])) {
            f->re = strdup(lfargs[1]);
            f->flags |= LF_REGEX;
        } else {
            fprintf(stderr,
                    "lf: '%s' is neither a directory nor a valid regular "
                    "expression.\n",
                    lfargs[1]);
            exit(EXIT_FAILURE);
        }
    }
    if (f->base_path == nullptr || f->base_path[0] == '\0')
        f->base_path = strdup(".");
    if (!f->sort) {
        init_find(f, argc, argv);
    } else
        sort_lf_output(f, argc, argv);
    if (f->count)
        fprintf(stderr, "Files: %zu\n", file_count);
    if (file_count == 0)
        return 1;
    return 0;
}

References expand_tilde(), file_count, init_find(), is_directory(), is_symlink_to_dir(), is_valid_regex(), LF_HIDE, LF_REGEX, lfargc, lfargs, sort_lf_output(), and strnz__cpy().

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scan_file()

int scan_file	(	char *	file_spec,
		const SearchFilters *	f,
		const unsigned char	effective_type )

scan a single file against search filters

Parameters

file_spec	specification of file being scanned
f	SearchFilters struct
effective_type	type of file being scanned

Returns

true if file selected, false otherwise

Definition at line 1088 of file lf.c.

                                                  {
    regmatch_t pmatch[2];
    bool stat_cached = false;
 
    while (1) {
        if (f->debug && (f->report_trace || f->report_all)) {
            printf("suppress %08b, effective %08b, lf_mask %08b, & %08b %s\n",
                   f->suppress_types, effective_type, lf_mask[effective_type], f->suppress_types & lf_mask[effective_type], file_spec);
        }
        if (f->suppress_types & lf_mask[effective_type])
            break;
        // Exclude non-matching files
        if (f->flags & LF_REGEX) {
            int reti =
                regexec(&f->compiled_re, file_spec, f->compiled_re.re_nsub + 1,
                        pmatch, f->reg_flags);
            if (reti == REG_NOMATCH) {
                if (f->debug && (f->report_info || f->report_all))
                    fprintf(stderr, "Regex no match: %s\n", file_spec);
                break;
            } else if (reti) {
                char errbuf[MAXLEN];
                regerror(reti, &f->compiled_re, errbuf, sizeof(errbuf));
                if (f->debug && (f->report_errors || f->report_all))
                    fprintf(stderr, "regex error: %s\n", errbuf);
                termination_status = EXIT_FAILURE;
                return 0;
            }
        }
        // Exclude matching files
        if (f->flags & LF_EXC_REGEX) {
            int reti =
                regexec(&f->compiled_ere, file_spec, f->compiled_re.re_nsub + 1,
                        pmatch, f->reg_flags);
            if (reti == 0) // Match
                break;
            if (reti != REG_NOMATCH) {
                if (reti) {
                    char errbuf[MAXLEN];
                    regerror(reti, &f->compiled_ere, errbuf, sizeof(errbuf));
                    if (f->debug && (f->report_errors || f->report_all))
                        fprintf(stderr, "Exclude regex error: %s\n", errbuf);
                    termination_status = EXIT_FAILURE;
                    return 0;
                }
            }
        }
        stat_cached = false;
        struct stat sb;
        //  Exclude files not owned by specified user
        if ((f->flags & LF_USER) && stat(file_spec, &sb) == 0) {
            stat_cached = true;
            if (sb.st_uid != f->user_id)
                break;
        }
        if (f->include_perms) {
            if (!stat_cached) {
                if (stat(file_spec, &sb) == 0)
                    stat_cached = true;
            }
            if ((f->include_perms & LF_IRUSR) && !(sb.st_mode & S_IRUSR))
                break;
            else if ((f->include_perms & LF_IWUSR) && !(sb.st_mode & S_IWUSR))
                break;
            else if ((f->include_perms & LF_IXUSR) && !(sb.st_mode & S_IXUSR))
                break;
            else if ((f->include_perms & LF_ISUID) && !(sb.st_mode & S_ISUID))
                break;
            else if ((f->include_perms & LF_ISGID) && !(sb.st_mode & S_ISGID))
                break;
        }
        if (f->before) {
            if (!stat_cached) {
                if (stat(file_spec, &sb) == 0)
                    stat_cached = true;
            }
            if (stat_cached && sb.st_mtime > f->before)
                break;
        }
        if (f->after) {
            if (!stat_cached) {
                if (stat(file_spec, &sb) == 0)
                    stat_cached = true;
            }
            if (stat_cached && sb.st_mtime < f->after)
                break;
        }
        if (f->file_size_min) {
            if (!stat_cached) {
                if (stat(file_spec, &sb) == 0)
                    stat_cached = true;
            }
            if (stat_cached && sb.st_size < f->file_size_min)
                break;
        }
        if (effective_type == DT_DIR) {
            char *file_p = file_spec;
            while (*file_p++ != '\0')
                ;
            *file_p = '/';
        }
        if (f->only_errors)
            break;
        file_count++;
        if (!f->count_silently) {
            if (file_spec[0] == '.' && file_spec[1] == '/')
                printf("%s\n", &file_spec[2]);
            else
                printf("%s\n", file_spec);
        }
        break;
    }
    return true;
}

References file_count, LF_EXC_REGEX, LF_IRUSR, LF_ISGID, LF_ISUID, LF_IWUSR, LF_IXUSR, lf_mask, LF_REGEX, LF_USER, and termination_status.

Referenced by finder().

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sort_lf_output()

void sort_lf_output	(	SearchFilters *	f,
		int	argc,
		char **	argv )

If sorting is requested, execute the finder and pipe its output to the sort command. We can achieve this by creating a child process that runs the sort command, and redirecting the output of the file finder to the input of the sort command using a pipe. The parent process will run the finder and write its output to the pipe, while the child process will read from the pipe and execute the sort command.

Definition at line 461 of file lf.c.

                                                             {
    char *eargv[MAXARGS];
    int eargc = 0;
    eargv[eargc++] = strdup("sort");
    if (f->sort_reverse)
        eargv[eargc++] = strdup("-r");
    eargv[eargc] = nullptr;
    int wstatus;
 
    // int save_fd = dup(STDOUT_FILENO); // save current STDOUT
    int fds[2];
    pipe(fds); // Create the pipes
 
    pid_t pid1 = fork();
    if (pid1 == 0) { // Child process
        // Child's STDIN will be redirected to the read end of the pipe, so that
        // the sort process will read the output of the finder from the pipe.
        close(fds[1]);              // Close the write end of the pipe in the child
        dup2(fds[0], STDIN_FILENO); // Clone child's read pipe to STDIN_FILENO
        close(fds[0]);              // Close the original read end of the pipe
        execvp(eargv[0], eargv);    // Execute the sort command
        fprintf(stderr, "Failed to execute sort: %s\n", strerror(errno));
        exit(EXIT_FAILURE);
    }
    // fclose(stdout);
    dup2(fds[1], STDOUT_FILENO);         // Clone write pipe to STDOUT_FILENO
    stdout = fdopen(STDOUT_FILENO, "w"); // Reopen STDOUT as a stream
    setvbuf(stdout, NULL, _IONBF, 0);    //  line buffering
    init_find(f, argc, argv);            // Initialize and transfer control to the finder
    fclose(stdout);
    close(fds[1]);
    wait(&wstatus);
    for (int i = 0; i < eargc; i++)
        free(eargv[i]);
    // fclose(stdout);
    // dup2(save_fd, STDOUT_FILENO);        // restore STDOUT
    // stdout = fdopen(STDOUT_FILENO, "w"); // Reopen STDOUT as a stream
    //
    // line buffering is essential to ensure that output is flushed to
    // the sort process in a timely manner, preventing deadlocks and
    // ensuring that the sort process can start processing input as soon
    // as it is available. Without line buffering, the output may be
    // buffered until the buffer is full, which could lead to delays in
    // processing and potential deadlocks if the sort process is waiting
    // for input that hasn't been flushed yet.
}

References init_find().

Referenced by main().

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Variable Documentation

active_tasks

atomic_int active_tasks = 0

Definition at line 134 of file lf.c.

Referenced by dequeue_dir(), and finder().

argp_program_bug_address

const char* argp_program_bug_address = "billxwaller@gmail.com"

Definition at line 54 of file lf.c.

argp_program_version

const char* argp_program_version = CM_VERSION

Definition at line 53 of file lf.c.

cond_var

pthread_cond_t cond_var = PTHREAD_COND_INITIALIZER

Definition at line 133 of file lf.c.

Referenced by dequeue_dir(), enqueue_dir(), finder(), and init_find().

debug_p

char* debug_p

Definition at line 142 of file lf.c.

doc

const char doc[]

Initial value:

= "lf list files\vIf specified, DIRECTORY is the top-level "
    "directory to search. REGULAR_EXPRESSION is a properly "
    "formatted regular expression for which matching files "
    "will be listed."

Definition at line 55 of file lf.c.

exec

char* exec

Definition at line 139 of file lf.c.

file_count

size_t file_count = 0

Definition at line 143 of file lf.c.

Referenced by main(), and scan_file().

file_types_p

char* file_types_p

Definition at line 140 of file lf.c.

lf_mask

unsigned char const lf_mask[15]

Initial value:

                        = {
0, 0b00000001, 0b00000010, 0, 0b00000100, 0, 0b00001000, 0, 0b00010000, 0,
0b00100000, 0, 0b01000000, 0, 0b10000000}

Definition at line 102 of file lf.c.

                                {
    0, 0b00000001, 0b00000010, 0, 0b00000100, 0, 0b00001000, 0, 0b00010000, 0,
    0b00100000, 0, 0b01000000, 0, 0b10000000};

Referenced by scan_file().

lfargc

int lfargc

Definition at line 137 of file lf.c.

Referenced by main().

lfargs

char* lfargs[3]

Definition at line 138 of file lf.c.

Referenced by main().

nthreads

unsigned int nthreads

Definition at line 62 of file lf.c.

Referenced by init_find().

perms_p

char* perms_p

Definition at line 141 of file lf.c.

qhead

TaskNode* qhead = NULL

Definition at line 130 of file lf.c.

Referenced by dequeue_dir(), and enqueue_dir().

qtail

TaskNode* qtail = NULL

Definition at line 131 of file lf.c.

Referenced by dequeue_dir(), and enqueue_dir().

queue_mutex

pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER

Definition at line 132 of file lf.c.

Referenced by dequeue_dir(), enqueue_dir(), and init_find().

shutdown

int shutdown = 0

Definition at line 135 of file lf.c.

Referenced by dequeue_dir(), and init_find().

termination_status

int termination_status = EXIT_SUCCESS

Definition at line 136 of file lf.c.

Referenced by finder(), and scan_file().

tm_info

struct tm tm_info

Definition at line 52 of file lf.c.